Quicktime File Format (2012-08-14).pdf

MetadataItem Information Atom (ID and flags)Item Information Atom (ID and flags)The optional item information atom contains information about the item: item-specific flags and item optionalidentifier. This ID must be unique within the metadata atom. To simplify assignment of item identifiers, themetadata header atom’s nextItemInfo field can be used as described in “Metadata Header Atom” (page 131).The item information atom must be present if the item has an assigned ID or has nonzero flags.No flags are currently defined; they should be set to 0 in this version of the specification.The item information atom is a full atom with an atom type of ‘itif’. This atom has the following structure:SizeA 32-bit unsigned integer that indicates the size in bytes of the atom structureTypeA 32-bit unsigned integer value set to 'itif'VersionOne byte that is set to 0.FlagsThree bytes that are set to 0.Item_IDAn unsigned 32-bit integer, unique within the container.NameThe Name atom is a full atom with an atom type of ‘name’. This atom contains a metadata name formatted asa string of UTF-8 characters, to fill the atom. It is optional. If it is not present, the item is unnamed, and cannotbe referred to by name. Names are not user visible; they provide a way to refer to metadata items. The maximumlength of a name may be limited in specific environments.No two metadata items may have the same name.This atom has the following structure:VersionOne byte that is set to 0.FlagsThree bytes that are set to 0.2012-08-14 | © 2004, 2012 Apple Inc. All Rights Reserved.141